Conventionally, polyimide resins collectively having an excellent heat resistance, electric property and mechanical property have been used for surface protection films and interlayer insulation films for semiconductor devices. However, while the semiconductor devices have been highly integrated and grown in size in recent years, it has been required to make sealing resin packages thinner and smaller, and systems such as surface mounting by LOC (lead on chip) and solder reflow have been employed. Thus, the polyimide resins which are ever more excellent in mechanical property and heat resistance have been needed.
Meanwhile, photosensitive polyimide obtained by imparting a photosensitive property to the polyimide resin itself has been used, and the use of this has characteristics that a pattern making process can be simplified and a complicated manufacture process can be shortened. Heat-resistant photoresists using conventional photosensitive polyimide or a precursor thereof, and their intended uses are well-known. In negative-types, the method in which a methacryloyl group is introduced into a polyimide precursor via an ester bond or an ion bond (see e.g., Patent Documents 1 to 4), soluble polyimide having photopolymerizable olefin (see e.g., Patent Documents 5 to 10), and self-sensitizing type polyimide having a benzophenone skeleton and having an alkyl group at an ortho position of an aromatic ring to which a nitrogen atom is bound (see e.g., Patent Documents 11 and 12) are available.
In the above negative-type, an organic solvent such as N-methylpyrrolidone is needed upon development. Thus, recently positive-type photosensitive resins which can be developed in an alkali aqueous solution have been proposed. In the positive-types, the method in which an o-nitrobenzyl group is introduced into the polyimide precursor via the ester bond (see, e.g., Nonpatent Literature 1), the method in which a naphthoquinone diazide compound is mixed with a soluble hydroxylimide or a polyoxazole precursor (see e.g., Patent Documents 13 and 14), the method in which naphthoquinone diazide is introduced into soluble polyimide via the ester bond (see e.g., Nonpatent Literature 2) and the method in which naphthoquinone diazide is mixed with a polyimide precursor (see e.g., Patent Document 15) are available.
However, the above negative-types functionally have a problem in resolution and a problem in that a yield ratio upon production is reduced depending on the intended use. In the above, the structure of the polymer to be used is limited, thus, a physical property of a finally obtained coat is also limited, and they are not suitable for multipurpose uses. Meanwhile, also in the positive-types, the sensitivity and the resolution are low owing to an absorption wavelength of a photosensitizer as the above, and the structure is limited. Thus, the positive-types have the similar problems.
Those obtained by mixing a diazonaphthoquinone compound with a polybenzoxazole precursor (see e.g., Patent Document 16), those in which a phenolic hydroxyl group has been introduced in place of carboxylic acid, such as those in which a phenol moiety has been introduced into polyamic acid via the ester bond (see e.g., Patent Document 17) are also available. However, in these, a development property is insufficient, and film thickness loss in an unexposed region and detachment of the resin from the substrate occur. For the purpose of improving such a development property and adhesiveness, those obtained by mixing polyamic acid having a siloxane moiety in a polymer skeleton (see e.g., Patent Documents 18 and 19) have been proposed, but a storage stability is deteriorated because of using polyamic acid as described above. In addition, those in which an amine terminal group is sealed with a polymerizable group for the purpose of improving the storage stability and the adhesiveness (see e.g., Patent Documents 20 to 22) are also proposed. However, they have the low sensitivity because a diazoquinone compound abundantly containing aromatic rings is used as an acid generator. An amount of the diazoquinone compound to be added is necessary to be increased. Thus, the mechanical property after being cured is remarkably decreased. Therefore, it is difficult to say that they are materials at practical levels.
[Patent Document 1] Japanese Patent Application Laid-Open No. S49-115541
[Patent Document 2] Japanese Patent Application Laid-Open No. S51-40922
[Patent Document 3] Japanese Patent Application Laid-Open No. S54-145794
[Patent Document 4] Japanese Patent Application Laid-Open No. S56-38038
[Patent Document 5] Japanese Patent Application Laid-Open No. S59-108031
[Patent Document 6] Japanese Patent Application Laid-Open No. S59-220730
[Patent Document 7] Japanese Patent Application Laid-Open No. S59-232122
[Patent Document 8] Japanese Patent Application Laid-Open No. S60-6729
[Patent Document 9] Japanese Patent Application Laid-Open No. S60-72925
[Patent Document 10] Japanese Patent Application Laid-Open No. S61-57620
[Patent Document 11] Japanese Patent Application Laid-Open No. S59-219330
[Patent Document 12] Japanese Patent Application Laid-Open No. S59-231533
[Patent Document 13] Japanese Patent Application Laid-Open No. S64-60630
[Patent Document 14] U.S. Pat. No. 4,395,482 Specification
[Patent Document 15] Japanese Patent Application Laid-Open No. S52-13315
[Patent Document 16] Japanese Patent Publication No. Hi-46862
[Patent Document 17] Japanese Patent Application Laid-Open No. H10-307393
[Patent Document 18] Japanese Patent Application Laid-Open No. H4-31861
[Patent Document 19] Japanese Patent Application Laid-Open No. H4-46345
[Patent Document 20] Japanese Patent Application Laid-Open No. H5-197153
[Patent Document 21] Japanese Patent Application Laid-Open No. H9-183846
[Patent Document 22] Japanese Patent Application Laid-Open No. 2001-183835
[Patent Document 23] Japanese Patent Application Laid-Open No. H3-763
[Patent Document 24] Japanese Patent Application Laid-Open No. H7-219228
[Patent Document 25] Japanese Patent Application Laid-Open No. H10-186664
[Patent Document 26] Japanese Patent Application Laid-Open No. H11-202489
[Patent Document 27] Japanese Patent Application Laid-Open No. 2001-56559
[Patent Document 28] Japanese Patent Application Laid-Open No. 2001-194791
[Patent Document 29] Japanese Patent Application Laid-Open No. Hyo 2002-526793
[Patent Document 30] U.S. Pat. No. 6,143,467 Specification
[Patent Document 31] Japanese Patent Application Laid-Open No. 2001-125267
[Nonpatent Literature 1] J. Macromol. Sci. Chem., A24, 12, 1407 (1987)
[Nonpatent Literature 2] Macromolecules, 23, 4796 (1990)